Messages in this thread | | | Date | Thu, 25 Apr 2019 12:22:10 +0200 | From | Peter Zijlstra <> | Subject | Re: x86/paravirt: Detect over-sized patching bugs in paravirt_patch_call() |
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On Thu, Apr 25, 2019 at 11:50:39AM +0200, Ingo Molnar wrote: > > * Peter Zijlstra <peterz@infradead.org> wrote: > > > On Thu, Apr 25, 2019 at 11:17:17AM +0200, Ingo Molnar wrote: > > > It basically means that we silently won't do any patching and the kernel > > > will crash later on in mysterious ways, because paravirt patching is > > > usually relied on. > > > > That's OK. The compiler emits an indirect CALL/JMP to the pv_ops > > structure contents. That _should_ stay valid and function correctly at > > all times. > > It might result in a correctly executing kernel in terms of code > generation, but it doesn't result in a viable kernel: some of the places > rely on the patching going through and don't know what to do when it > doesn't and misbehave or crash in interesting ways. > > Guess how I know this. ;-)
What sites would that be? It really should work AFAIK.
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